Abstract:Fructooligosaccharides (FOS) have received particular interest because of their excellent biological and functional properties for using as a prebiotic compound. The strain Aspergillus niger CGMCC No. 6640 with independent intellectual property rights was found capable of producing FOS using sucrose as the substrate. To produce FOS using free-whole-cell biotransformation by A. niger 6640, the effects of production parameters on the biotransformation of sucrose were investigated by HPLC with the column of Rezex RCM-Monosaccharife Cat. The catalysate concentration of the Nystose (or 1F-Fructofuranosylnystose), kestose, sucrose, glucose and fructose were simultaneously detected, and their retention time was 8.403 min, 8.853 min, 9.705 min, 11.473 min and 14.683 min, respectively. The free-whole-cell concentration and substrate concentration positively affected the maximum FOS yield. However CaCl2 concentration negatively affected the FOS yield. The free-whole-cell concentration, the initial reaction pH, the temperature for catalysis, biotransformation time and sucrose concentration were 60 g/L, 7.0, 33 ℃, 40 h and 600 g/L, respectively. Under the optimal conditions were as follows, the FOS contents reached 314.60 g/L. In summary, the free-whole-cell biocatalyst of A. niger 6640 can effectively produce FOS indicating a potential for industrial production.
